Mechanical truck door position indicator

ABSTRACT

A back door position indicating device for a delivery truck, which can be removably mounted easily without the use of complicated tools or mounting devices to a handle at the rear of the truck near the roll up door, and which pivots to a door open indicating position when the rear door is open, so that driver will become aware of the open door by viewing the indicating device through his rear view mirror before driving off.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an indicator for a rear roll up door of a truck which comes in the view of the driver when the door is open.

2. Description of the Related Art

Often drivers of trucks forget to close the rear door and drive off without being aware of the open door, so that merchandise can be lost. An accelerating truck could deposit cargo on the highway producing very dangerous traffic conditions. There is a need for a device to alert the driver through his rear view mirror that the rear door is open.

Di Grazia (U.S. Pat. No. 3,924,558) shows a rear door indicator with a mounting means which includes mounting blocks and contact cement (col. 2, lines 53-59).

Clark (U.S. Pat. No. 6,374,766) shows a signal device which bends or flexes when struck (abstract) and which includes a lighting system (FIG. 7A).

There is a need for an improved door position indicator which is easy to manufacture and mount on the truck. Such an improved device is mounted without the use of adhesives or special mounting members and is operable without the use of electrical, magnetic or lighting devices.

SUMMARY OF THE INVENTION

The present invention is a position indicating device which can be mounted without the use of complicated tools or mounting devices. To mount the inventive device, a signal assembly is clamped to a handle at the rear of the truck near the roll up door. With the door open, a flexible connector, such as a rope, is tied to the cable of the spring counter weight of the door; the indicator is pivoted to the door open indicating position, about parallel to the ground, and the other end of the flexible connector is tied to the non-indicating end of the pivoting indicator. When the door is closed, the flexible connector and weight falls, causing pivoting of the indicator to a non-indicating position. The indicator is quickly and easily removably mounted with no alteration of truck parts by drilling, punching, welding, etc.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the nature of the present invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

FIG. 1 is a view of the rear end of the truck body, showing the door closed and the indicator in the non-indicating position with rod 14 passing through the opening formed by the door handle.

FIG. 2 is a view of the rear end of the truck body, showing the door open and the indicator pivoted outwardly to be in the view of the driver through his rear view mirror.

FIG. 3 is a partial side view of the indicator assembly showing the indicator end of the assembly.

FIG. 4 is a perspective view of one of the saddle clamps used to secure the weight to the weighted end of the indicator assembly.

FIG. 5 is a partial side view of the indicator assembly showing the weight secured to the end between two saddle clamps.

FIG. 6 is a partial view of the rear door showing the flexible connector secured to the cable of the spring counter weight with a locking c-clamp.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1, the door is shown in the closed position with the indicator reflector 10 out of the view of the driver through his rear view mirror 16. The indicator assembly is clamped to a handle 12 near the truck door, by means of clamp 11. The flexible connector 13 is attached to weight 19 at one end of the indicator assembly and to cable 15 at the lower end of the door. The flexible connector is preferably a strong braided rope. It could take many forms such as a flexible metal chain, which could then also serve as a weight replacing weight 19. Weight force can be replaced or augmented by other forces such as magnetic or spring forces. The rope is preferably about 4 feet in length and about 3/16 inch in diameter. The braided rope can consist of layers of braided synthetic or natural materials or can comprise a braided sheath. The handle 12 is a long u-shaped cylindrical member with legs which are short compared to the handle length and with flat mounting surfaces substantially perpendicular to the short legs.

FIG. 2 shows the truck rear door in an open position with the indicator assembly reflector 10 (preferably a red reflector) pivoted outwardly into the driver's view through his rear view mirror 16. The flexible connector 13 has been displaced upwardly with the end of the cable of the door spring counter weight which movement caused the pivoting of the reflector 10. A red flag or other indicating means can replace reflector 10.

FIG. 3 is a partial side view of the indicator end of the indicator assembly showing the reflector 10 which is a disc about 3 inches in diameter. It is preferably red in color and is attached to one end of rod 14. Reflector 10 can be various shapes such as spherical, triangular, etc. Rod 14 can be made from a variety of materials such as fiberglass, reinforced plastic material, various other plastic materials, metals etc. Preferably the rod is about 1/4 inch in diameter. The indicator assembly is attached to a handle at the rear of the truck near the door by clamp 21, which is about 1½ inch long and about 1 inch wide with a clamp screw 20 which is about ¼ inch in diameter. The indicator rod 14 is attached to offset lug 22 by set screw 25 which is about ¼ inch in diameter. Offset lug 22 is about 1½ inches long and about ⅜ inches wide and is placed about 7½ inches from the weighted end of the rod. The other end of offset lug 22 is secured to clamp 21 by a bolt 23 which is about ¾ inches long and about 3/16 inches in diameter. Bolt 23 carries nut 24, and the offset lug (which is sturdily attached to rod 14) pivots about the bolt. Clamp 21 can have threaded apertures in both jaws. FIG. 4 shows one of the saddle clamps used to secure the weight to the other end of the rod. The clamps consist of u-bolt 41, saddle 43 and nuts 42. The u-bolt is about 1 1/8 inches long and the legs are about ¼ inch diameter. Clamp 21 can have jaws which are roughened or serrated to increase holding power.

FIG. 5 shows the weight end of rod 14 with weight 26 secured between two saddle clamps. The weight is a nut about 1 ¾ inches long. The use of various weights are possible. Weights could be adhesively secured to the rod. Various clamps, including various c-clamps could be substituted for the saddle clamps. The flexible connector 13 is secured to the weight end of rod 14 by tying it about one leg end of u-bolt 41 between the saddle 43 and a nut 42. The other end of the flexible connector 13 (FIG. 6) is tied to the bottom of cable 15 of the spring counter weight that is used for the door. In the preferred embodiment, the connection is made using a locking c-clamp 60. The connector could be tied directly around the cable.

FIG. 6 shows the flexible connector 13 secured to cable 15 by locking c-clamp 60. The locking c-clamp has threaded legs which are bridged by a common threaded nut. 

1. A method of mounting a rear door position indicating assembly on a cargo carrying truck with a roll up rear door comprising; attaching said indicating assembly to a truck frame part, securing one end of a flexible connector to said position indicating assembly, with the door open, securing the other end of said flexible connector to a door part while adjusting said indicator assembly to an open door indicating position, and closing said rear door to cause said flexible connector to pivot said indicating assembly to a non-indicating position.
 2. The method of claim 1 wherein said flexible connector is a strong rope.
 3. The method of claim 1 wherein said attaching is by clamping.
 4. The method of claim 1 wherein said truck frame part is a handle near said roll up door.
 5. The method of claim 1 wherein said door part is the cable of the spring counter weight of the roll up door.
 6. A rear door position indicating assembly for a roll up door of a cargo carrying truck comprising; a rod having a position indicating reflector on one end, an offset lug having one end secured to said rod; the other end of said offset lug receiving a bolt therethrough, said bolt providing a pivot means for said rod, said bolt being secured to a clamp, said clamp being secured to a handle on the truck frame near said door, a flexible connector having one end secured to the other end of said rod and the other end secured to the cable of the spring counter weight of the door.
 7. The indicating assembly of claim 6 wherein said other end of said rod carries a weight.
 8. The indicating assembly of claim 7 wherein said weight comprises a nut carried by said rod and secured between two saddle clamps clamped to said rod.
 9. Apparatus for indicating to the driver of a cargo carrying truck the position of the rear roll up door comprising, first means for securing an indicator assembly to a truck frame part, second means for securing one end of a connector to a part of the indicator assembly, third means for securing the other end of said connector to a truck rear door part, said indicator assembly, first means, second means and third means constructed and arranged to position an indicator in an indicating position when said door is open and in a non-indicating position when said door is closed.
 10. The apparatus of claim 9 wherein said indicator assembly comprises a rod with a reflector attached to one end and one end of said connector attached to the other end.
 11. The apparatus of claim 10 wherein the other end of said connector is attached to the cable of the spring counter weight of the roll up door.
 12. The apparatus of claim 11 wherein said connector is a strong flexible rope.
 13. The apparatus of claim 12 wherein said strong rope is a braided rope.
 14. The apparatus of claim 9 wherein said first means is a clamp for securing said indicator assembly to a handle on the truck frame.
 15. The apparatus of claim 9 where said indicator protrudes outwardly and is visible in the driver's rear view mirror when the door is open and pivots to a non-indicating position when the door is closed.
 16. The apparatus of claim 10 wherein the other end of the rod carries a weight.
 17. The apparatus of claim 9 wherein said indicator assembly is easily removable from the truck.
 18. The apparatus of claim 9 wherein said means for securing requires no permanent alteration of truck parts.
 19. The apparatus of claim 9 wherein said means for securing requires no machining operations such as drilling, sanding or punching.
 20. The apparatus of claim 9 wherein said indicator is a reflector. 